Circuit interrupter



J. B. M NElLL ETAL 2,669,629

CIRCUIT INTERRUPTER Feb. 16, 1954 Filed July 22, 1950 F ig.2.

6 Sheets-Sheet 2 WITNESSES: INVENTORS //j[ JohnB.MccNeill,WinthropM.Leeds and Ben amin RBaker.

a ATTOR Y Feb. 16, 1954 J. B. M NElLL ET AL 2,669,629

CIRCUIT INTERRUPTER Filed July 22, 1950 6 Sheets-Sheet 3 Fig.4. 1 44".LXKRIIS WITNESSES: INVENTORS John B.-MucNeill,Wimhmp M. Leeds I e 45and Bcn'omin RBoker.

Feb. 16, 1954 J. a a g ET AL 2,669,629

CIRCUIT INTERRUPTER Filed July 22, 1950 6 Sheets-Sheet 4 Fig.5.

WITNESSES: 30 INVENTC'RS John B. MocNeilI ,Winthrop M. Leeds May andBenjamin RBoker.

Feb. 16, 1954 J MacNElLL ETAL 2,669,629

CIRCUIT INTERRUPTER Filed July 22, 1950 6 Sheets-Sheet 5 Fig.6.

WITNESSES:

John B. MccNeillMfinthrop M. Leeds and BeniominRBoker.

ATTOR Y CIRCUIT INTERRUPTER 6-Sheets-Sheet 6 Filed Jul 22. 1950 Fig.1

INVENTORS John B. MocNeillQNinthrop M.-Leeds.

and Benjamin P. Baker. 654 2U ATTORN WITNESSES: 1 1

Patented Feb. 16, 1954 CIRCUIT mcrE RUPTER John B. MacNeill and WinthropM. Leeds, Pittsburgh, and Benjamin P. Baker, Turtle Creek, Pa.,assignors toWestinghouse Electric Corporation, East PittsburghPennsylvania Pa., a corporation of Application July 22 195i), derial No. 175,375 21 Claims. (01. 200-150) 1 This invention relates to circuitinterrupters, in general, and more particularly to improved opcratingmechanisms and improved interrupting structures therefor.

A general object of our invention is to provide an improved circuitinterrupter which will more effectively interrupt the circuittherethrough than has heretofore been achieved.

Another object is to provide a circuit interrupter having an improvedcontact operating sequence and "an improved isolating switcharrangernent.

Still a further object is to provide an improved high-speed operatingmechanism for a circuit interrupter of the foregoing type.

Another object is to associate in a liquid break type "of circuitinterrupter, a liquid moving piston, particularly effective during lowcurrent interruption, and to provide an improved high-speed operatingmechanism'for the interrupter and also for causing the charging motionof the piston.

Another object is to provide "an improved liquid break type of circuitinterrupter in'which the volume of liquid utilized is at a minimum,resulting the so-called oil-poor construction, 'in which an improvedinterrupter and mechanism arrangement is provided to result inhigh-speed, simple and trouble-free performance.

A subsidiary object is to provide an improved operating leverage systemfor effectively and rapidlyactuating the foregoing structure.

Another object is to provide an improved resilient intermediate contactfor a circuit inter,- rupter of the type having two movable contactsseparating in substantially opposite directions from an intermediatecontact to thereby establish f two serially related arcs.

Further objects and advantages will readily become apparent upon readingthe following specification, taken in conjunction with the drawings, inwhich:

Figure l is a fragmentary vertical sectional view taken through' theinterrupting part of a circuit interrupter embodying our principles, andshown in the closed ircuitpos'ition;

Fig. 2 is a fragmentary vertical sectional view l, but the dispositionof the several parts being shown .in the fully open .circuit ,positionof the interrupter;

Fig. 4 is an enlarged ,vertical sectional view through our improved-intermediate contact .arrangement;

Fig. 5 is a view corresponding with that of Fig. 2, butshowi'ng thedisposition of the isolating contact and also of the operating linkagein the fully open circuit position of the interrupter;

Fig. 6 is a fragmentary vertical sectional view taken through a modifiedtype of interrupter, embodying the principles of our invention and shownin the closed circuit position; and

Fig. 7 is a view corresponding with that of Fig. 6, but indicating thedisposition of several parts in the fully open circuit position of theinterrupter.

Referring to the drawings, and more particularly to Figs. 1 and 2thereof, the reference numeral l designates generally a circuitinterrupter of the so-called liquid-poor type, that is one utilizing aminimum volume of liquid, such as circuit breaker oil. As shown, theinterrupter l includes an outer cylindrical weather-proof casing 23,consisting of a suitable ceramic material, such as porcelain or thelike, under compression, and an interiorly disposed insulating cylinder3, preferably placed under tension. The inner casing 3 contains asuitable arc extinguishing fluid, such as oil, filled to the level 4.Within the inner cylindrical casing 3 is disposed an arc extinguishingunit, generally designated by the reference character 5 and including anupwardly movable pressure-generating rod-shaped contact 6, anintermediate contact 1 and a lower movable interrupting contact 8.Cooperating with the lower end of the interrupting contact 8 is amovable rod-shaped disconnect contact 8, which, in the open circuitposition of the interrupter, as shown in Fig. 5, provides a disconnectgap in the circuit.

Associated with the pressure-generating arc passage I0 is a pistonstructure generally designated by the reference character H, andincluding a movable piston l3, movable in an operating cylinder M andhaving a slotted piston rod l5 connected thereto. The piston I3 isbiased downwardly in a working direction by a battery of compressionsprings H, which are charged, or compressed, during the closingoperation of the interrupter, as will be explained more fullyhereinafter.

Preferably we provide an operating lever l8 pivotally mounted at itsright-hand end at a pivot l9 guided to move horizontally, and having itsleft-hand end pivotally connected, as at 2D, to the upper end of themovable pressure-generating contact 6. It will be observed that thepressure-generating contact 6 is biased upwardly in a circuit openingdirection by a compression sp in 2 ;actuating lever 23 is also provided,being pivotally mounted, intermediate the end thereof, at a stationarypivot 25. The left-hand end of the actuating lever 23 is connected, by alostmotion connection 25, to the upper end of the piston rod l5. Morespecifically, this lost-motion connection 25 includes a pin 25 securedto the left-hand end of the actuating lever 23, said pin 25 movingvertically within an elongated slot 21 provided at the upper end of thepiston rod 15. Consequently, during the closing operation of theinterrupter, when the actuating lever 23 rotates in a clockwisedirection about the stationary pivot 25, the pin 25 causes upward orcharging motion of the piston 13 in opposition to the biasing actionexerted by the battery of compression springs i6. During the openingoperation, as will be more fully explained hereinafter, the contactstructure is free to open independently of operation of the piston 53 byvirtue of the presence of the lost-motion connection 25.

The right-hand end of the actuating lever 23 is pivotally connected, asat 28, to both an intermediate point of the operating lever l3 and alsoto the upper end of an insulating operating rod 3-5.

As shown in the drawing, the piston chamber 3| is connectedhydraulically to the pressuregenerating arc passage ii) by a verticalconduit 32, formed upon the alignment of holes provided .in suitablyconfigured plates, and also by a conduit 33, hydraulically connected toa second vertical conduit 35 likewise formed by a registration of holesprovided in the plate structure.

The pressure-generating chamber or passage in is formed by the use of aplurality of aperl,

erating are 35 by a passage of the oil through the plurality of orifices35, the liquid then passes downwardlythrough two vertically disposedconduits, not shown, interconnecting the pressuregenerating chamber iiiwith the interrupting chamber 55. In other words, a plurality of pairsof vent passages 45 are provided intermediate .the orifices 35 whichpermit the passage of oil to flow downwardly through the two previouslymentioned vertical conduits, not shown, and into the interruptingchamber 39 to strike the interrupting arc ii (Fig. 3) establishedbetween the intermediate contact 'l and the lower movable interruptingcontact 3.

After passing through a plurality of pairs of inlet passages, not shown,leading into the interrupting chamber 35, the oil passes through aplurality of orifices 52 to exhaust out of the unit through oppositelydisposed vent passages The particular plate arrangement is not a part ofour invention, and consequently it is only briefly described. Referencemay be had to United States Patent 2,445,442, issued July 20, 1948, toWinthrop M. Leeds and Robert E. Friedrich. Also reierence may be had toUnited States patent application filed April 16, 1947, Se-

Inlet passages rial No. 741,865, now United States Patent 2,530,952,issued November 21, 1950 to Francis J. Fry and assigned to the assigneeof the instant application.

During the interruption of relatively high currents,' the pressuregenerated at the pressuregenerating are 35 is adequate for speedyinterruption of the interrupting are ll, and in such a case, thepressure may be so high within the pressure-generating arc passage is asto act back through the conduits 32, 35 and stall downward motion of thepiston l3. After are interruption, however, the pressure falls and thepiston completes its stroke, sending a flushing flow of oil through thearcing chambers. It is only during the interruption of relatively lowamperage currents, when the pressure generated at thepressure-generating are 35 is low, that the piston i3 is free to movedownwardly, as caused by the battery of compression springs [6, to forceoil into the pressure-generating passage or chamber l5 and subsequentlydownwardly into the interrupting chamber 39 to efiect extinction of theinterrupting arc 5! established therein.

Although the arcs 35, 3!, have been drawn in Fig. 3 for purposes ofdescription, nevertheless, in fact, when the contact structure hasreached the position shown in Fig. 3, the arcs 35, 4|, will, at thistime, have been extinguished.

Referring to l, which shows more clearly the intermediate contactstructure I, it will be apparent that we have provided two electricallyinterconnected contacts 45, d5 of cup-shaped configuration, which serveas seats for a compression spring 46, which provides resilient contactpressure between the contacts 5, 44 and 8, "55. A pair of flexiblestraps 7 are employed to electrically interconnect the contacts 44, 45in series. The straps d! are riveted to flanges 44a, 55a, respectively,of contacts 44, 45. The flanges 44a, 35a serve as stops to limitextension of the intermediate contact I, the flange L da striking aplate 48, and the lower flange 45a striking a plate 59. As mentioned,the provision of compression spring 46 provides contact pressure betweenthe several pairs of contacts immediately adjacent to the point ofactual contact so that there is no need for supplying resilienceelsewhere in the operating leverage system.

It will be observed that the lower movable contact 8 is biaseddownwardly, in a circuit-opening direction, by a compression spring 5|,the latter being seated between a plate 52 and a flange 53 secured tothe lower end of the movable interrupting contact 8. Immediately belowthe flange 53 is a contact portion 55, which serves, in effect, as arelatively stationary disconnect contact cooperating with the movabledisconnect contact 9 to establish an isolating gap, in the fully opencircuit position of the interrupter, as shown in Figs. 3 and 5.

To limit the downward travel of the movable interrupting contact 8, theflange 53 strikes a stop portion 55 provided by a lower electrostaticshield 56.

Referring to Figs. 2 and 5, which respectively show the closed and opencircuit positions of the operating parts, it will be observed that wehave provided an operating leverage system, generally designated by thereference numeral 58, and including an operating lever 59, fixedlymounted adjacent its left-hand end, as viewed in Figs. 2 and 5, to astationary pivot 60.

The right-hand end of the operating lever 59 is pivotally connected, asat 6!, to a guidelink 62, one end of which is pivotally connected, as at63, to the lower end of the movable disconnect contact 9, and the otherend of which is guided by a roller 54 rolling in a horizontal race track65. By the proper proportioning of these links and levers, the pin 63,to which contact 9 is attached, will be constrained to move in asubstantially straight line by principles well known in the art.

To cause opening and closing motion of the operating lever 59, weprovide a toggle, generally designated by the reference character 66,and including a toggle link 61 and a second toggle link 68. A knee pin69 interconnects the toggle links 67, G8. The upper end of the togglelink 81 is pivotally connected, as at 70, to the operating lever 59intermediate the ends thereof. The lower toggle link 68 is fixed to arotatable shaft H, having a crank arm 12 which is pivotally connected,at T3, to the upper end of a pull rod 14. Thus, downward closing motionof the pull rod l4 causes clockwise rotation of the shaft H and hencestraightening of the toggle 66 to effect thereby counterclockwiserotation of the operating lever 59 about the pivot 69, to effect upwardclosing motion of the disconnect contact 9. Opening operation, which isachieved by upward motion of the pull rod 14, permits the toggle G6,which is almost on-center in the closed position of thev interrupter, tobreak, and to permit, upon collapse, clockwise rotation of the operatinglever 59 and hence downward or opening motion of the movable disconnectcontact 9.

A pin 16, secured to and movable with the operating lever 59, engagesnear the end of the closing stroke, the left-hand end of an actuatinglever ll, the latter being stationarily pivoted at ?8 intermediate theends thereof. The righthand end of the actuating lever 71 is pivotaliyconnected, as at T9, to the lower end of the operating rod 30. Aspreviously described, downward motion of the operating rod 39 effectscharging of the piston structure I I and also closing motion of theupper pressure-generating contact 6.

Preferably, the movable disconnect contact 9 is guided by anelectrostatic shield member 89,

as at 8!, and also contact fingers 82 are provided, which bear againstthe sides of the movable disconnect contact 9. It will be observed thatthe casing 2 is supported upon a metallic F provided, interiorly of thecasing 2a, being placed under tension so that the lower ceramic casing2a will be under compression.

The lower end of the casing 2a and the inner insulating cylinder 3a issupported .upon a suitable base framework, not shown, but which isconventional in the art. If desired, a second interrupter i may bemounted upon the same base framework, and the two interrupters electrically connected in series so that twice the voltage may beinterrupted.

The opening operation of the. interrupter will now be explained: Duringthe: opening operation, the pull rod E4 is moved upwardly, to therebybreak the toggle 66, permittng collapse of the same to thereby causeclockwise rotation of the operating lever :59. Also the clockwiserotation of the operating lever 59 allows the pin "Hi-to permit theactuating lever 1:1 ;to rotate in: a counterclockwise directionaboutthestationaryipivot 18 to permit the springs 18, 2| to effect workingmotion of the piston l3 (assuming the pressure is low) and upwardopening travel of the movable pressure-generating contact 6.

During this time, the clockwise rotation of the operating lever 59 hascaused the guide link 62 to pull the movable disconnect contact 9downwardly, thereby permitting the compression spring 5| to causedownward opening motion of the interrupting contact 8. It will be notedthat the lower end 53 of the interrupting contact 8 remains in abuttingengagement with the upper end of the movable disconnect contact 9 untilthe latter passes below the electrostatic shield 56, at which time thecontinued downward lowering motion of the movable interrupting contact 8is halted by the flange 53 striking the stop portion 55 of theelectrostatic shield 56.

During the opening of the contact structure, the pressure-generating are35 has been established between the contacts I, 6, and an interruptingarc has been established between the intermediate contact 1 and theinterrupting contact 8. Fluid now, in the manner previously described,efiects extinction of the interrupting are H, so that the circuit isbroken, and continued downward travel of the movable disconnect contact8 inserts an isolating or disconnect gap in the circuit, as shown inFig. 5. Fig. 5, consequently, shows the disposition of the leveragesystem 58 in the fully open circuit position of the interrupter.

The closing operation of the interrupter will now be explained: To closethe interrupter, the pull rod is is forcibly pulled downwardly. Thiscauses straightening of .the toggle .66 to thereby effectcounterclockwise rotation of the operating lever 59, about the pivot 80,to thereby effect upward closing motion oi the moi/table disconnectcontact a, as caused by closing motion Of the guide link 62.

Near the end of the closing operation, when the toggle 66 is in afavorable position to give a substantial mechanical advantage to thepull on rod M with respect to the applied loads, at this time, the pin76, secured to and movable with the operating lever'fiil, strikes theleft-hand end of the actuating lever TI and forcibly causes clockwiserotation of the same. The clockwise rotation of the actuating lever Tlforcibly pulls the insulating operating rod 30 downwardly, to eilectthereby closing motion of the pressuregenerating contact 16 against thebiasing .action exerted by the compression spring 2|, and also effectsupward charging motion of the piston {.3 in opposition to the biasingaction exerted by the compression springs lffi.

Substantially simultaneously with closing of the contact 6, i, theinterrupting contact ,8 strikes the intermediate contact 7, havingpreviously been engaged and moved upwardly by the lower movabledisconnect-contact 9,. As :a result, there is a practically simultaneousclosing ofboth the pressure-generating contacts '!,,'6 withthemterrupting contacts 7, 8. The circuit is then closed through theinterrupter 1,, and the to gle 66 is-brought close to itson-center-position, while the operating mechanisminot. shown) islatched.

Figs. 6 and 7 illustrate a modification of our invention inwhich,although the arc extinguishing unit 5a is practically .the same as itwas-in Figs. 1 and 3, certain 'significantchanges'have been-made. Forinstance, the lower movable inrterrupting contact Bais pivotallyconnected, .at 87, to .an operating. .lever 88,;pivoted :at 89to astationary pivot. flhearightehandvcndgof .theiopcrating lever 88 ispivotally connected, at 90, to the operating rod 30a. The stationarypivot 89, supporting the operating lever 88, is provided by anelectrostatic shield member 56a, which, at the lower end thereof, isprovided with a pair of finger contacts 9|, which bear against the sidesof the lower movable disconnect contact rod 9a. This arrangementincreases the speed of the lower contact 8a with respect to theoperating rod 30a.

We further provide a modified type of leverage system, generallydesignated by the reference numeral 92, and including a toggle 93,comprising a toggle link 94 and a toggle plate 95 stationarily pivotedat a fixed pivot 96. A pull rod 14a is pivotally connected, as at 97, tothe toggle plate 95. A knee pin 98 pivotally interconnects the togglelinks 94, 95. The upper end of the toggle link 94 is pivotallyconnected, as at 99, to an operating lever I00, the right-hand end ofwhich is pivotally connected, at IOI, to a stationary pivot.

The left-hand end of the operating lever I is pivotally connected, as atI92, to an actuating link I03, the upper end of which (Fig. 6) ispivotally connected, as at I04, to the lower end of the movabledisconnect contact rod 9a. The left-hand end of the actuating link I03,as viewed in Figs. 6 and 7, is guided by a roller I moving in ahorizontal race track I06.

Also pivotally connected to the stationary pivot IOI is a rotatableactuating plate or member I0! pivotally connected, as at I08. to thelower end of the operating rod 30a.

Pivotally connected to the toggle plate 95, as at N19, is an actuatinglever H0, which is biased to the position shown in Fig. 6, by suitableleaf springs III, the purpose for which will be more fully apparenthereinafter. During the closing operation of the interrupter, startingfrom the position shown in Fig. 7, the pull rod 14a is forcibly moveddownwardly. This causes clockwise rotation of the toggle plate 95 aboutthe stationary pivot 96, to effect thereby straightening of the toggle93. Also the actuating lever H9, which is engaged with a hooked portionH2 of the plate member I01, forcibly causes counterclockwise rotation ofthe plate member I01 about the stationary pivot I0], to effect therebydownward closing motion of the operating rod 30a. Near the end of theclosing operation, an actuating portion I I3 of toggle plate 95 engagesa portion I I4 of the plate member Ifll to continue the counterclockwiserotation of the plate member I01 about the stationary pivot IIlI,thereby effecting release of the actuating lever I I0 from the portion I12 of the plate member I07. Thus, in the fully closed circuit positionof the interrupter, as shown in Fig. 6, the actuating lever H0 is freefrom the plate member I07, and the actuating portions H3, H4 of theplates 95, I91, respectively, prevent upward opening motion of theoperating rod 30a.

It will be observed that during the closing operation, the contactstructure, including the contacts 6, 8a, have efiected engagement priorto engagement of the upper end of the movable disconnect contact 9a withthe finger contacts 9|, so that the circuit is closed only at thecontacts 9a, 9| and not at the contacts disposed within the unit 5a.Thus, any contamination due to prestriking on the closing stroke willoccur in clear liquid outside of the unit 5a, and not within the unit5a. If such contamination were to take place within the unit 5a duringthe closing operation, instead of between the fingers 9| and the 8movable disconnect contact 9a in relatively clean oil, then thedielectric strength within the unit 5a would be lowered for a subsequentopening operation. Such a lowering of dielectric strength would tend tocause prolonging of the arcing period during such a subsequent openingoperation.

An opening operation of the modified type of interrupter shown in Figs.6 and 7 will now be described: Assuming the interrupter to be closed, asshown in Fig. 6, and that it is desired to effect an opening operation,suitable mechanism not shown, is actuated to cause upward openingmovement of the pull rod 74a. Practically immediately thereafter theactuating portions H3, H4 separate so that immediately the operating rod38a is free to move upwardly due to the biasing action exerted by thesprings I6, H to effect opening of the contact structure and operationof the piston structure I I, entirely independently of opening operationof the toggle 93 and related mechanism effecting opening operation ofthe movable disconnect contact 9a.

From the foregoing it will be seen that opening operation of the movabledisconnect contact 9a is independent of opening of the contact structurewithin the unit 5a. As the pull rod Ma continues to move upwardlythereby effecting continued collapse of the toggle 93, the operatinglever Ifiii moves in a counterclockwise direction about the fixed pivotIill causing substantially clockwise rotation of the actuating link I93about the horizontally moving pivot 505 as a center, thereby effectingdownward opening motion of the movable disconnect contact rod 9a. By thetime that the movable disconnect contact 911 separates from the contactfingers 9|, the arcs 35, H within the unit 5a will have beenextinguished, and the circuit consequently interrupted. Continued upwardtravel of the pull rod 14a finally effects a separation between thefinger contacts 9| and the movable disconnect contact 9a to effect anisolating gap within the circuit in the fully open circuit position ofthe interrupter, as shown in Fig. 7. As the linkage approaches its finalposition, link H0 snaps into engagement with the hooked end I I2 of theplate member it? ready for the next closing operation.

From the foregoing two embodiments of our invention, it will be apparentthat we have provided an improved interrupting structure utilizing asingle arc extinguishing unit with an improved piston arrangement in aliquid-poor construction. Since there is simultaneous contact separationand contact closure in both embodiments, the arrangement is particularlysuitable for three cycle interrupting times at voltages of kv. andabove. As mentioned, two such column type interrupting structures I maybe used in series to double the voltage which can be interrupted.

It will moreover be apparent that the operating mechanism is simple andefiicient. It will be noted that with the first arrangement disclosed,as set forth in Figs. 1-5, the lower grid contact 8 is operated directlyby the long stroke disconnect contact 9, while the upper contact 6 isoperated by the insulated rod 99. Moreover, in the first arrangement,this insulated rod 30 operates in tension and is moved only in thelatter part of the breaker closing stroke, when the toggle levers E7, 68are in an advantageous position. The resilient intermediate contact Igives contact pressure close to the contact surfaces, and avoidsresilient joints in the linkages.

In the second arrangement, shown in Figs. 6

and 7, the isolating contact So has no mechanical connection whatsoeverwith the interrupting contacts, and, therefore, can be made of verylight construction. Also during the closing operation, the interruptercontacts are closed first and the circuit finally established at theisolating contacts 9a, 9|. During the opening stroke, in the secondarrangement, the initial motion of the operating mechanism 92 releasesthe interrupter contacts, so that their opening speed is entirelyindependent of the speed of the isolating contact 9c and its associatedmechanism.

It will also be noted in the second arrangement, that the closing loadis very uniform, in that the interrupter contacts and piston pumpingmechanism are moved during a large portion of the closing stroke. Thisis in contrast to that of the first arrangement where the interruptercontacts and piston are charged only at the end of the closing stroke.Each arrangement has its advantages in certain situations.

Although we have shown and described particular structures, it is to beclearly understood that the same were merely for the purpose ofillustration, and that changes and modifications may readily be madetherein by those skilled in the art, without departing from the spiritand scope of the appended claims.

We claim as our invention:

1. A circuit interrupter including an are extinguishing unit, a movablecontact movable adjacent one end of the unit, an operating rod foractuating said contact movable longitudinally of the unit, a. movabledisconnect contact movable adjacent the other end of the unit, anoperating mechanism including a rotatable operating lever, the operatinglever being rotatable about a substantially fixed pivot adjacent one endthereof, means connecting the movable disconnect contact with theoperating lever, an actuating lever, means connecting the operating rodwith the actuating lever so as to constantly move therewith, meansindependent of the actuating lever for effecting motion of the operatinglever, and a pin secured to and movable with the operating lever tocause rotation of the actuating lever during the closing operation.

2. A circuit interrupter including an are extinguishing unit, a movablecontact movable adjacent one end of the unit, an operating rod forctuatin said contact movable longitudinally of the unit, a movabledisconnect contact movable adjacent the other end of the unit, anoperating mechanism including a rotatable operating lever, the operatinglever being rotatable about a substantially fixed pivot adjacent one endthereof, means connecting the movable disconnect contact with theoperating lever, an actuating lever, means connecting the operating rodwith the actuating lever so as to constantly move therewith, a togglelinkage for rotating the operating lever, and a pin secured to andmovable with the operating lever to rotate the actuating lever near theend of the closing operation when the toggle linkage is in a nearlyexpanded condition.

3. A circuit interrupter including an are extinguishing unit, a movablecontact movable adjacent one end of the unit, a movable contact movableadjacent the other end of the unit, an operating rod for actuating bothmovable contacts movable longitudinally of the unit, a movabledisconnect contact movable adjacent said other end of the unit, anoperating mechanism including a rotatable toggle plate, an operatinglever, means interconnecting the movable disconnect contact with theoperating lever, a toggle link cooperable with the toggle plate toeffect rotation of the operating lever, a rotatable actuating plate,means connecting the operating rod with the actuating plate, and anactuating lever pivotally mounted upon the toggle plate to efiectrotation of the actuating plate.

4. A circuit interrupter including an are extinguishing unit, a movablecontact movable adjacent one end of the unit, an operating rod foractuating said movable contact movable longitudinally of the unit, amovable disconnect contact movable adjacent the other end of the unit,an operating mechanism including a rotatable toggle plate, meansinterconnecting the movable disconnect contact with the toggle plate, arotatable actuating plate, means connecting the operating rod with theactuating plate, and an actuating lever pivotally mounted upon thetoggle plate to eifect rotation of the actuating plate.

5. A circuit interrupter including an are extinguishing unit, a movablecontact movable ad jacent one end of the unit, an operating rod foractuating said movable contact movable longi tudinally of the unit, amovable disconnect contact movable adjacent the other end of the unit,an operating mechanism including a rotatable toggle plate, meansinterconnecting the movable disconnect contact with the toggle plateincluding a toggle link, a rotatable actuating plate, means connectingthe operating rod with the actuating plate, and an actuating leverpivotally mounted. upon the toggle plate to effect rotation of theactuating plate.

6. A circuit interrupter including an arc extinguishing unit, a movablecontact movable adjacent one end of the unit, an operating rod foractuating said movable contact movable longitudinally of the unit, amovable disconnect contact movable adjacent the other end of the unit,an operating mechanism including a rotatable toggle plate, meansinterconnecting the movable disconnect contact with the toggle plate, a1'0- tatable actuating plate, means connecting the operating rod withthe actuating plate, an actuating lever pivotally mounted upon thetoggle plate to effect rotation of the actuating plate, and an actuatingportion provided on the toggle plate to engage an actuating portion ofthe actuating plate to effect release of the actuating lever from theactuating plate.

7. A circuit interrupter including an are ex tinguishing unit, a movablecontact movable adjacent one end of the unit, a movable contact movableadjacent the other end of the unit, an operating rod for actuating bothmovable contacts movable longitudinally of the unit. a movabledisconnect contact movable adjacent said other end or" the unit, anoperating mechanism including a rotatable toggle plate, an operatinglever, means interconnecting the movable disconnect contact with theoperating lever, a toggle link cooper-able with the toggle plate toeffect rotation of the operating lever, a rotatable actuating plate,means connecting the operating rod with the actuating plate, anactuating lever pivotally mounted upon the toggle plate to effectrotation of the actuating plate, and an actuating portion provided onthe toggle plate to engage an actuating portion of the actuating plateto effect release of the actuating lever from the'actuating plate.

8. A circuit interrupter including an are extinguishing unit, a movablecontact movable adjacent one end of the unit, an operating rod foractuating said movable contact movable longitudinally of the unit, amovable disconnect contact movable adjacent the other end of the unit,an operating mechanism including a rotatable toggle plate, meansinterconnecting the movable disconnect contact with the toggle plate, arotatable actuating plate pivoted intermediate the ends thereof, meansconnecting the operating rod with one end of the actuating plate, and anactuating lever pivotally mounted upon the toggle plate to engage theother end of the actuating plate.

9. A circuit interrupter including an are extinguishing unit, a movablecontact movable adjacent one end of the unit, an operating rod foractuating said movable contact movable longitudinally of the unit, amovable disconnect contact movable adjacent the other end of the unit,an operating mechanism including a rotatable toggle plate, meansinterconnecting the movable disconnect contact with the toggle plate, arotatable actuating plate pivoted intermediate the ends thereof, meansconnecting the operating rod with one end of the actuating plate, anactuating lever pivotally mounted upon the toggle plate to engage theother end of the actuating plate, and an actuating portion provided onthe toggle plate to engage an actuating portion of the actuating plateto effect release of the actuating lever from the actuating plate.

10. A circuit interrupter including an are extinguishing unit, a movablecontact movable adjacent one end of the unit, piston structure disposedadjacent said one end of the unit including a movable piston, meansbiasing the movable piston in a working direction, a piston rod, anoperating lever pivotally mounted adjacent one end thereof to asubstantially fixed pivot and connected to the movable contact adjacentthe other end thereof, an actuating lever pivotally mounted intermediatethe ends thereof to a substantially stationary pivot and connectedadjacent one end thereof to the piston rod, an operating rod. movablelongitudinally of the unit, means interconnecting the operating rod withboth the actuating lever adjacent the other end thereof and also to theoperating lever intermediate the ends thereof so that when the operatingrod is pulled in tension toward the other end of the are extinguishingunit the movable contact is moved to the closed position and the movablepiston is charged against the force of the biasing means.

11. A circuit interrupter including an arc-extinguishing'unit, a movablecontact movable adjacent one end of the unit, a relatively stationaryintermediate contact, a second movable contact movable adjacent theother end of the unit, means biasing the said second movable contactaway from the intermediate contact, a movable disconnecting contactmovable adjacent said other end of the unit and carrying the secondmovable contact therewith during the closing operation against thebiasing action exerted by said biasing means, the movable disconnectingcontact separating away from the second movable contact during theopening operation to insert an isolating gap into the circuit, anoperating rod for actuating the first said movable contact, and meansfor moving the operating rod in a direction longitudinally of thearc-extinguishing unit and toward the other end of the unit during theclosing operation.

12. A circuit interrupter including an arc-extinguishing unit, a movablecontact movable adjacent one end of the unit, a relatively stationaryintermediate contact, a second movable con tact movable adjacent theother end of the unit, means biasing the said second movable contactaway from the intermediate contact, a movable disconnecting contactmovable adjacent said other end of the unit and carrying the secondmovable contact therewith during the closing operation against thebiasing action exerted by said biasing means, the movable disconnectingcontact separating away from the second movable contact during theopening operation to insert an isolating gap into the circuit, levermeans connected to the first said movable contact, an operating rodconnected to said lever means and movable longitudinally of thearc-extinguishing unit, and means for moving the operating rod in adirection longitudinally of the arc-extinguishing unit and toward theother end of the unit during the closing operation.

13. A circuit interrupter including an arc-extinguishing unit, a movablecontact movable adjacent one end of the unit, an operating rod foractuating said contact movable longitudinally of the unit, a movabledisconnect contact movable adjacent the other end of the unit, anactuating lever mounted intermediate the ends thereof on a relativelystationary pivot, the operating rod being connected to one end of theactuating lever, means for operating said movable disconnect contact,and said means engaging the other end of the actuating lever during atleast a part of the closing operation to effect longitudinal motion ofthe operating rod and hence closing motion of the movable contact.

14. A circuit interrupter including an arc-extinguishing unit, a movablecontact movable adjacent one end of the unit, lever means connected tosaid movable contact, an operating rod connected to said lever means foractuating said contact movable longitudinally of the unit, a movabledisconnect contact movable adjacent the other end of the unit, anactuating lever mounted in tel-mediate the ends thereof on a relativelystationary pivot, the operating rod being connected to one end of theactuating lever, means for operating said movable disconnect contact,and said means engaging the other end of the actuating lever during atleast a part of the closing operation to efiect longitudinal motion ofthe operating rod and hence closing motion of the movable contact.

15. A circuit interrupter including an arc-extinguishing unit, a movablecontact movable adjacent one end of the unit, lever means pivotallymounted adjacent one end thereof to a relatively stationary pivot andconnected to said movable contact adjacent the other end thereof, asecond movable contact movable against the other end of the unit, anoperating lever pivotally mounted intermediate the ends thereof adjacentsaid other end of the unit, the second movable contact being connectedto an end of the operating lever, a longitudinally-extending operatingrod movable logitutdinally of the unit and connected to the other end ofthe operating lever, the operating rod also being connected to saidlever means intermediate the ends thereof so that motion of theoperating rod toward the other end of the unit efiects closing motion ofboth movable contacts.

16. A circuit interrupter including an arcextinguishing unit, a movablecontact, piston structure including a movable piston, means biasing themovable piston in a working direction.

a piston rod, an operating lever pivotally mounted adjacent one endthereof to a substantially fixed pivot and connected to the movablecontact adjacent the other end thereof, an actuating lever pivotallymounted intermediate the ends thereof to a substantially stationarypivot and connected adjacent one end thereof to the piston rod, andoperating means connected with both the actuating lever adjacent theother end thereof and also to the operating lever intermediate the endsthereof so as to efiect simultaneous motion of both the movable contactand the piston structure.

17. A circuit interrupter including an arcextinguishing unit, a movablecontact movable adjacent one end of the unit, an operating rod foractuating said contact movable longitudinally of the unit, a movablecontact movable adjacent the other end of the unit, an operatingmechanism including a rotatable operating lever, the operating leverbeing rotatable about a substantially fixed pivot adjacent one endthereof, means for operating the second said movable contact by rotationof said operating lever, an actuating lever, means connecting theoperating rod with the actuating lever so as to constantly movetherewith, and means secured to and movable with the operating lever tocause rotation of the actuating lever during the closing operation.

18. A circuit interrupter including an arcextinguishing unit, a movablecontact movable adjacent one end of the unit, an operating rod foractuating said contact movable longitudinally of the unit, a movablecontact movable adjacent the other end of the unit, an operatingmechanism including a rotatable operating lever, the operating leverbeing rotatable about a substantially fixed pivot adjacent one endthereof, means for actuating the second said movable contact by rotationof said operating lever, an actuating lever, means connecting theoperating rod with the actuating lever so as to constantly movetherewith, and means secured to and movable with the operating lever andmaking separable connection to the actuating lever to cause rotation ofthe latter at least during a portion of the closing operation.

19. A circuit interrupter including an are extinguishing unit, a movablecontact movable adjacent one end of the unit, an operating rod foractuating said contact movable longitudinally of the unit, a movablecontact movable adjacent the other end of the unit, an actuating levermounted intermediate the ends thereof on a relatively stationary pivot,the operating rod being connected to one end of the actuating lever,means for operating said second movable contact, and said means engagingthe other end of the actuating lever during at least a part of theclosing operation to efiect longitudinal motion of the operating rod andhence closing motion of the movable contact.

20. A circuit interrupter including an arc extinguishing unit, a movablecontact movable adjacent one end of the unit, lever means connected tosaid movable contact, an operating rod connected to said lever means foractuating said contact movable longitudinally of the unit, a secondmovable contact movable adjacent the other end of the unit, an actuatinglever mounted intermediate the ends thereof on a relatively stationarypivot, the operating rod being connected to one end of the actuatinglever, means for operating said second movable contact, and said meansengaging tie other end of the actuating lever during at least a part ofthe closing operation to eifect longitudinal motion of the operating rodand hence closing motion of the movable contact.

21. A circuit interrupter including an are extinguishing unit, a movablecontact movable adjacent one end. of the unit, an operating rod foractuating said movable contact movable longitudinally of the unit, asecond movable contact movable adjacent the other end of the unit, anoperating mechanism including a rotatable toggle plate, meansinterconnecting the second movable contact with the toggle plate, arotatable actuating plate, means connecting the operating rod with theactuating plate, and an actuating lever pivotally mounted upon thetoggle plate to effect rotation of the actuating plate.

JOHN B. MACNEILL. WINTHROP M. LEEDS. BENJAMIN P. BAKER.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,123,870 Haskins Jan. 5, 1915 2,102,768 Trencham et al. Dec.21, 1937 2,201,881 Bryant et al. May 21, 1940 2,467,760 Ludwig et al.Apr. 19, 1949 2,477,788 Cumming Aug. 2, 1949 2,495,192 Webb Jan. 17,1950 FOREIGN PATENTS Number Country Date 500,731 Great Britain Feb. 13,1939

